Mayfly residue is delaying 2021 Chevrolet Tahoe, GMC Yukon shipments

If you ever feel too small to make a difference in the world, think of the mayflies that have ruined the paint of over 2,600 Chevrolet Tahoe and GMC Yukon SUVs. Also called fishflies, these tiny aquatic insects are causing a shocking amount of damage to the vehicles that sometimes requires a trip to the body shop to fix.

General Motors officials told industry trade journal Automotive News that the company has had to delay some Tahoe and Yukon shipments to clean off black residue they believe comes from the mayflies. Some stores have chosen to take the SUVs as-is, but they’ve had to spend hours removing bug guts from body panels, windows, and wheels; one dealer received a Tahoe with a hood so badly damaged that it needed to be repainted. 

Both SUVs are built in the same Arlington, Texas, factory, and they’re stored near a lake where swarms of mayflies tend to congregate after flying out of the water. Female mayflies normally live for less than five minutes, while males have a two-day lifespan, but they spend enough time flying around to leave some kind of residue. Precisely what they’re tarnishing the paint with is up in the air. They don’t eat, adult mayflies don’t have mouths, so they’re not relieving themselves. They’re not eggs, either, because those are normally laid on the water.

Less than 100 units of the Tahoe/Yukon twins ended up in the hands of dealers with black residue, according to General Motors. It recently sent all of its stores a bulletin instructing them to clean the SUVs with bug remover, wash them with a pressure washer or another brushless system, polish the paint with a foam pad, and thoroughly inspect it under high-intensity fluorescent lighting. Meanwhile, it’s in the process of cleaning the vehicles parked on its storage lot in Texas, and it expects they will all be in like-new condition by the middle of September.

“Plant personnel are rapidly cleaning vehicles so that they arrive to our dealers and customers in flawless condition,” a company spokesperson told Automotive News. General Motors’ Arlington factory also builds the Suburban and the Yukon XL, but there’s no word on whether these models are getting soiled by bugs as well.

Tahoe and Yukon inventories might be low across the nation until General Motors cleans and dispatches the SUVs on its storage lot. How it will prevent insect-related issues in the future remains to be seen.